Preparation of cyano derivatives of amic acids and products



Patented May 11,1954

A ED PATENT -=oFI F161;

' PREPARATION OF CYANO DERIVATIVES 40F r AMIC Aoms AND PRODUCTS Marvin R' 'F1;aeii 1;, Wadsworth, Ohio, -assig'nor to The B. 'F Goodrich Company, New" York, 7. rN. Y., a corpdrati'on of NewrYork *NoDrawing., :Applioation December 16;:1 950, Serial No. 201,237

IB'CIaQimS. (Cl. 260-1281) invention ,riaat s r ,to a method for Lthe preparation ,of .ii'cya'no" derivatives of. am ic acids, manyjer which derivatives are new compounds, and pertains monerpartimilany to .tl'l6p i6paration fif such "compoun s by" the ,rea'ctioh [of 7. betalabtdiis with 'j-alpha-cy'anoi moaocarboxyncam amides. t

.2 acidification. When the reaction is carriedout in asubstantially anhydrous medium such as in solutioninan alcohol which is a solvent for the 'frltljsdiis'closed 1U. 'SffPatent' aabeassto s 7 wherein, it is hydrogenmr ;.an;a;1k.rlr3d a atfithe reactiverhydrogen ,-:.a.t om on the alpha, carbon of thec-zcyanor-acid such; manner that th u etar :carbomatom ofihteabeta-lactone;attaches tog-the alhpacarbomatormofthezamide:to-formalipha cyano derivatives of amic tacids jilhese compounds are believed not to rhave been prepared heretofore. Also, an""'additio nal linkage of the carbonylcarbon *atom l ofthebe'ta-"l'emtone tothe a mido nitrogen atom may occur simultaneously with the'linkage or the beta-carbon atom of the beta lactone' to thealpha carbon atom of the amide, in which event analicyclic' cyano derivativefiof an amic acid, that is, --a 3-cyanoglutarimide, L is formed. T-he 3-cyanoglutariinides maybe readily-hydrolyzed to give'aliphatic' cyano derivativesofamic acid which are a1sobelieved to'benew compounds.

Either an aliphatic-orf-an;alicyclic ccinipound may be obtained as the principal product Y of the reaction betweena beta-lactone and an alphacyano monocarb'oxylic acid amide depending upon the conditions under-which the reaction is carried; out. For example, when the reactionis carried: out, in aqueous solution andin the presence of than alkalinejcatalystjthe[salt of an aliphatic cyanoesubstituted ,amicmacidhisl iqli llfid,

I from which the free acid is readily obtained by amide and in the presence of an v,- alln1tli metal catalyst an alicyclic B-cyanbglutarimid is obtained. Such an alicyclic compound is readily converted to an aliphaticcyano-substituted amic acid by a simple alkaline hydrolysis process. The compounds obtained by .the hydrolysis process are new chemical (iqm ouhds. The above-described reactions proceed substantially asfollows:

I. Aqueous medium with alkaline catalyst R R1 R1 B1 R1 Aqueous/ are", belieyed to R emigrean,

Medium/ fgijlkaltu tal 31 Zilkalirie: hydrolysis In the above reaction equations R represents hydrogen or a lower alkyl radical and R1 represents hydrogen or an alkyl radical.

Typical alpha-cyano monocarhoxylic acid amides having the structure shown hereinabove and which react with beta-lactones in accordance with this invention include cyanoacetamide, alpha-cyano propionamide, alpha-cyano butyramide, alpha-cyano valeramide, alpha-cyano caproamide, alpha-cyano caprylamide, alphacyano pelargonamide, alpha-cyano capramide and the like. Especially preferred are those alpha-cyano monocarboxylic acid amides in which the radical R is hydrogen or a lower alkyl radical such as methyl, ethyl, propyl or butyl.

For the reason that it is most readily obtainable in commercial quantities and at relatively low cost, beta-propiolactone is the preferred beta-lactone for use in the present process. However, other saturated aliphatic beta-lactones which possess the structure wherein each R is a member of the class consisting of hydrogen and lower alkyl radicals may also be used advantageously. Typical examples of such beta-lactones include in addition to beta-propiolactone, beta-butyrolactone, beta-isobutyrolactcne, beta-n-valerolactone, beta-ism valerolactone, betaisopropyl-beta-propiolactone, beta-ethyl-beta-butyrolactone, alpha methylbeta-propiolactone, alpha, alpha-dimethyl-betapropiolactone, and the like. Of these beta-lactones there are preferred those which are water soluble; beta-lactones containing from 3 to 6 carbon atoms possess this property.

In carrying out the reaction of rbeta-lactones with alpha-cyano monocarboxylic acid amides in aqueous alkaline solution, any alkali metal hydroxide such as sodium hydroxide, potassium hydroxide and the like, or other alkaline material may be utilized. When the reaction is carried out in alcohol solution any of the alkali metals may be used as catalysts. These metals occur in group 1A of the periodic system and include lithium, sodium, potassium, rubidium, cesium and virginiuin. In practice, it is preferred that the alkali metal be dissolved in an alcohol solvent therefor such as ethanol, propanol, butanol, hexanol, 2-propanol and the like. By the use of a solvent for the catalyst the formation of an alkali metal derivative, a probable intermediate in the reaction of this invention, is facilitated. The quantity of catalyst utilized is not critical and may be varied considerably. In general, however, it may be stated that it is desirable to utilize from 0.5 to 2.0 moles of the alkali metal for each mole of the alpha-cyano monocarboxylic acid amide although larger or smaller amounts may be utilized if desired.

The quantity of the beta-laetone utilized is also not critical. Accordingly, the lactone and the alpha-cyano monocarboxylic acid amide may be brought together in equimolar quantities, the amount stoichiometrically required for the reaction to occur or if desired a stoichiometric excess of either reactant may be used. It has been found, however, that the optimum molar ratio of alpha-cyano monocarboxylic acid to beta-lactone to catalyst is approximately 1:1:1.

Generally, the reaction of the present invention is carried out at temperatures in the range of about C. to 80 C. However, temperatures below 0 C. and higher than C. are also operative although the yields obtained are not so high as those obtained when the preferred temperatures are employed.

The following specific examples are intended to illustrate more fully the process of this invention, but are not intended to be construed as limiting the scope thereof, for there are, of course, numerous possible variations and modifications. In the examples all parts are by Weight.

Example I 46 parts (2 moles) of sodium are added rapidly to 945 parts of absolute ethyl alcohol and the solution is cooled to about 35 C. 189 parts (2.25 moles) of cyanoacetamide are then added to the resulting solution with vigorous stirring until the cyanoacetamide becomes well dispersed (about 30 minutes). While continuing the stirring 144 parts (2 moles) of beta-propiolactone are added over a 30 minute period and the reaction mixture allowed to digest for 2 hours at a. temperature in the range of 35-50 C. The reaction mixture is then acidified with 113 parts (1.1 mole) of concentrated sulfuric acid and the crystalline product which forms is removed by filtration, washed and recrystallized from water, whereupon 34 parts of 3-cyanoglutarimide (M. P. 207-8 0.; Nitrogen analysis; theoretical value 20.3%, found 20.4%) are obtained.

Example II Example I is repeated except ibeta-isovalerolacto-ne is substituted for beta-propiolactone. l-A-dimethyl-3-cyanoglutarimide, a white solid, is obtained in good yield.

Eatample III Example I is repeated except that alpha-cyano propionamide is substituted for cyanoacetamide. 3-methyl-3-cyanoglutarimide is obtained in substantial yield, although the yield is not as high as that secured in Example I.

Example IV 8.9 parts (0.05 mole) of 3-cyanoglutarimide are dissolved in 50 parts of water containing 2 parts (0.05 mole) of sodium hydroxide. The solution is heated at 50 C. for one hour, cooled to 25 C. and acidified, whereupon a crystalline product separates. The solid material is removed by filtration. 4.5 parts (59%) of 2-cyanoglutaramic acid (M. P. -145 C. with gas evolution) are obtained after recrystallization from alcohol and water.

Example V A suspension of 168 parts (2 moles) of cyanoacetamide in a solution of 80 parts (2 moles) of sodium hydroxide in 600 parts of water is prepared and maintained at 15 C. The suspension is then stirred for 5 minutes, cooled to 5 C. and 144 parts (2 moles) of beta-propiolactone are added whereupon the temperature rises to '7 2 C. After 30 minutes the solution is cooled to 20 C. and acidified with 113 parts of concentrated sulfuric acid. Upon filtration 50 parts of 4-cyanoglutaramic acid (M. P. 168-1'70 C. with gas evolution) are obtained.

structure risgobtained. v v a c {El e aliphatic cyano-substituted samic .zacids prepared; by the lmethodcof this ginverition ;.are very valuable compounds. ,aEZoreXample, theyare useful as medicinalintermediates and as intermediates in the preparation of various chemical compounds form'any' otherpurposes. They are also of value in the-fieldsof insecticides, fungioides and herbicides: as well ,as for many other a. r p r s iemhqdiih t cd theginvenfiqn have'bendisclosed herein, it is not, intended to limit the invention solely thereto, for it is obvious that many modifications, including substitution of equivalent materials and variations in the proportions of materials used are within the spirit tand scope fof theinvention, as defined. in the appended j claims.

in The bres iic j mmin materia ctone c, of"?th'e .lfo'rniula 'whereinaeach R1 is a member of the class-consisting of hyfdrogen andclower alkyl radicals: and -an ;alpha-ic'y'ano .monoc'arboxylic :acid 'amid'e .of the. formula wherein R is a member of the classyconsisting of hydrogen and alkyl radicals, thereby to obtain a cyano derivative of an amic acid.

2. The method which comprises bringing together in the presence of an alkali metal catalyst dissolved in an alcohol solvent therefor a betalactone of the formula wherein each R1 is a member of the class consisting of hydrogen and lower alkyl radicals, and

6 -an-;:a1pha,-cyano q-mono'eai-boxyllc acid amide of the formula No-ofi-( lrrm wherein R isisa memberof the 1 class consisting of hydrogen and alkyl radicals;lithereby-toiobtain a compound of the formula wherein R and Riihave the same significance as above.

3. Themethodwhich comprises bringing together in the presence of an alkali metalcat yst dissolved" in an alcohol solvent therefjo betapropiolactone and an alpha-cyano monocarboxylic acid amide of the formula NC C'H( %-'N'HQ 9 wherein R 'is' a' member of "the class 'consjs of h drogen and lower, alkyl radieals, thereby to obtain a co-mpoun'd of" the fformula wherein Y R has' the s'ame significance as} above. 4. The method of-claim-B wherein the alphacyano wmono'carboxylic acid amide is cyanoa'ceta- 'mide,thecatalyst sodium, and the anchor solvent is ethanol, the product obtained -bein'g'f-ecyanoglutarimidec Y 5. The method which comprises bringing t'ogether in the presenceof an alkali metal catalyst a beta-lactone' of the formula wherein each -;R1 is a member ,-oithe class; consisting of hydrogen and lowenialkylradicals; and an alpha-cyano monocarboxylic: acid :amider of. the formula 7 wherein R is ajimember of fi'the class consisting of hydrogen and alkyl radicals, thereby to obtain a 3-vcyanoglutarimide of the structure and hydrolyzing said 3-cyanoglutarimide, thereby to obtain a 2-cyano derivative of an amic acid.

wherein each R1 is a member of the class con sisting of hydrogen and lower alkyl radicals, and an alpha-cyano monocarboxylic acid amide of the formula wherein R is a member of the class consisting of hydrogen and alkyl radicals, and then acidi fying the reaction mixture thereby to obtain a compound of the formula CN R1 i i t wherein R and R1 have the same significance as above.

8. The method of claim 8 wherein the betalactone is beta-propiolactone, the compound recovered possessing the formula wherein R is a member of the class consisting of hydrogen and alkyl radicals.

9. The method which comprises bringing together beta-propiola'ctone and cyanoacetamide in aqueous alkaline solution, and then acidifying the reaction mixture, thereby to obtain -cyanoglutaramic acid.

10. As new chemical compounds, acids of the formula ti t wherein R is a member of the class consisting of hydrogen and saturated alkyl groups having from 1 toabout 8 carbon atoms and each R1 is a member of the class consisting of hydrogen and saturated lower alkyl radicals.

11. As new chemical compounds, acids of the formula wherein R is a member of the class consisting of hydrogen and saturated alkyl groups having from 1 to about 8 carbon atoms.

12. 4-cyanoglutaramic acid.

13. As new chemical compounds, acids of the formula.

wherein R is a member of the class consisting of hydrogen and saturated alkyl groups having from 1 to about 8 carbon atoms and each R1 is a member of the class consisting of hydrogen and saturated lower alkyl radicals.

14. As new chemical compounds, acids of the formula wherein R is a member of the class consisting of hydrogen and saturated alkyl groups having from 1 to about 8 carbon atoms.

15. Z-cyanoglutaramic acid.

16. The method which comprises bringing together in the presence of an alkaline catalyst and a solvent for the reaction mixture (1) a betalactone of the formula wherein each R1 is a member of the class consisting of hydrogen and lower alkyl radicals, and (2) an alpha-cyano monocarboxylic acid amide of the formula wherein R. is a member of the class consisting of hydrogen and alkyl radicals, said solvent having F the general formula YOI-I, wherein Y is a member of the class consisting of hydrogen and saturated lower alkyl radicals free of active methylene groups, thereby to'obtain a cyano derivative of amic acid.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,391,251 Long Dec. 18, 1945 2,396,626 Wiest et al Mar. 12, 1946 2,460,536 Rogers Feb. 1, 1949 2,505,459 Bruson et a1. Apr. 25, 1950 2,506,050 Warner et al. May 2, 1950 OTHER. REFERENCES Barthe, Beilstein (Handbuch, 4th ed.), vol. II, D. 814 (1920). 

10. AS NEW CHEMICAL COMPOUNDS OF THE FORMULA
 13. AS NEW CHEMICAL COMPOUNDS, ACIDS OF THE FORMULA 